\documentclass[]{article}
\setlength{\pdfpagewidth}{8.5in} \setlength{\pdfpageheight}{11in}
\begin{document}
\begin{tabular}{lcccc} \hline
 & (1) & (2) & (3) & (4) \\
VARIABLES & specialized\_rankfirst & specialized\_proportion & specialized\_listed & d\_enroll\_specialized \\ \hline
 &  &  &  &  \\
1.grupo\_gen & 0.00525 & 0.00310 & 0.00321 & 0.00379 \\
 & (0.0079) & (0.0048) & (0.0097) & (0.0073) \\
2.grupo\_gen & 0.00448 & 0.00163 & 0.00580 & 0.00472* \\
 & (0.0029) & (0.0017) & (0.0039) & (0.0027) \\
 &  &  &  &  \\
Observations & 33,861 & 33,861 & 33,861 & 33,861 \\
R-squared & 0.066 & 0.023 & 0.090 & 0.057 \\
 Mean of dependent variable & 0.0817 & 0.0250 & 0.159 & 0.0693 \\ \hline
\multicolumn{5}{c}{ Robust standard errors in parentheses} \\
\multicolumn{5}{c}{ *** p$<$0.01, ** p$<$0.05, * p$<$0.1} \\
\end{tabular}
\end{document}
